The Effects of Acute Exercise Intensity on Episodic Memory and False Memory

Dilley, Emma Kate
(2019)
The Effects of Acute Exercise Intensity on Episodic Memory and False Memory.
Undergraduate thesis,
under the direction of Paul Loprinzi from
Health, Exercise Science and Recreation Management,
The University of Mississippi.

Abstract

The Effects of Acute Exercise on Episodic Memory and False Memory
Previous experimental work demonstrates that acute exercise may enhance episodic memory performance. However, limited research has examined the extent to which acute exercise influences false memory production, and no studies, to date, have examined whether there is an intensity-specific effect of acute exercise and true and false memories. Thus, the present experiment evaluated the effects of acute exercise on episodic memory and false memory. A three-arm, parallel, between-group randomized controlled trial was employed, with participants (Mage = 20.8 years) randomized into a moderate-intensity exercise group (15-minute bout of treadmill exercise at 50% Heart Rate Reserve; N = 20), a high-intensity exercise group (15-minute bout of treadmill exercise at 80% Heart Rate Reserve; N = 20), or a control group (15 minutes of sitting; N = 20). Episodic and false memory were both assessed using the Deese-Roediger-McDermott (DRM) paradigm. For the number of words recalled across each of the 6 lists, there was a significant main effect for list (F(list)=10.2, P<.001, η2p=.15), marginally significant main effect for group F(group)=2.7, P=.07, η2p=.09), but no list by group interaction effect (F(list x group)=1.00, P=.44, η2p=.03). Those in the high-intensity exercise group recalled significantly (P<0.05) more words than the control group. For the false word recall, there was not a significant main effect for list (F(list)=2.15, P=.06, η2p=.04), group (F(group)=2.20, P=.12, η2p=.07) or list by group interaction (F(list x group)=1.27, P=.24, η2p=.04), but across various lists, high-intensity acute exercise was associated with a greater rate of false memories. For the memory recognition task, there was no main effect for word type (F=.85, P=0.46, η2p=.01), group (F=.85, P=.43, η2p=.03), word type by
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group interaction (F=.97, P=.44, η2p=.03), recall by group interaction (F=1.03, P=.41, η2p=.04), or word type by recall by group interaction (F=1.13, P=.32, η2p=.04). However, there was a main effect for recall (F=64.3, P<.001, η2p=.54) and a word type by recall interaction (F=182.6, P<.001, η2p=.77). That is, participants, across all three experimental conditions, were more likely to perceive the studied and critical lure words as being “old” (i.e., that they previously were exposed to them during the study session). These findings suggest that high-intensity exercise may enhance true episodic memories, and, possibly, increase the rate of select false memories. We discuss these findings in the context of how different acute exercise intensities may have unique and differential effects on underlying mechanistic processes related to true and false episodic memory.
Keywords: fuzzy trace theory; hippocampus; prefrontal cortex; recollection